The effects of short-term nicotine administration on behavioral and oxidative stress deficiencies induced in a rat model of Parkinson's disease.
ABSTRACT We previously demonstrated that a 6-hydroxydopamine (6-OHDA) induced lesion of substantia nigra (SN), which is a very well known animal model of Parkinson's disease, resulted in memory deficits and increased brain oxidative stress. Also, recent reports had suggested that nicotine from smoke may contribute, at least in some parts, to the apparent neuroprotective effect of tobacco use in Parkinson's disease.
In this way, in the present study we were interested to examine the effects of low-dose nicotine administration (5 days, 0.3 mg/kg/day) in a rat model of Parkinson's disease, on behavioral parameters from Y-maze or shuttle-box task and also on the oxidative stress markers from the temporal lobe, which is one of the most vulnerable cortical area to oxidative stress effects.
The administration of nicotine resulted in significant improvements of short-term memory, as seen in the Y-maze task, as well an increase of conditioned avoidance responses and decreased number of escape failures in the shuttle-box task. Additionally, an increase in the specific activity of glutathione peroxidase and a decrease of the lipid peroxidation processes is reported. Moreover, we found a significant correlation between the behavioral results from the Y-maze and shuttle-box tasks and the levels of oxidative stress markers.
Taken together our data suggest that short-term administration of low-dose nicotine facilitates memory processes and improves the oxidative stress status of the brain, after a 6-OHDA induced lesion of the SN.
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ABSTRACT: Emerging evidences suggest that nicotine exerts a neuroprotective effect on Alzheimer's disease (AD), yet the precise mechanism is not fully elucidated. Here, HT22 cells were exposed to amyloid beta protein fragment (Aβ)1-42 to mimic the pathological process of neuron in AD. We hypothesized that cannabinoid receptor CB1 is involved in the nicotine-induced neuroprotection against Aβ1-42 injury in HT22 cells. CB1 expression in HT22 cells was investigated by immunocytochemistry and Western blot. The injury of HT22 cells was evaluated by cellular morphology, cell viability, and lactate dehydrogenase (LDH) release. The apoptosis of HT22 cells was assessed by flow cytometry and expressions of Bcl-2 and Bax. The results demonstrated that nicotine markedly upregulated CB1 expression, increased cell viability, ameliorated cellular morphology, decreased LDH release, and reduced the apoptotic rate of HT22 cells exposed to Aβ1-42 for 24 h, while the blockade of CB1 or the inhibition of protein kinase C (PKC) partially reversed the neuroprotection. Furthermore, the blockade of CB1 reversed nicotine-induced PKC activation in HT22 cells exposed to Aβ1-42. These results suggest that CB1 is involved in the nicotine-induced neuroprotection against Aβ1-42 neurotoxicity, and the neuroprotection may be dependent on the activation of PKC.Journal of Molecular Neuroscience 09/2014; 55(3). DOI:10.1007/s12031-014-0422-4 · 2.76 Impact Factor
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ABSTRACT: Nicotine has been reported to exert certain protective effect in the Parkinson's and Alzheimer's diseases. Whether it has a similar action in focal cerebral ischemia was unclear. In the present study, rats received either an injection of (-)-nicotine hydrogen tartrate salt (1.2 mg/kg, i.p.) or the vehicle 2 h before the 120 min middle cerebral artery occlusion. Neurological deficits and histological injury were assessed at 24 h after reperfusion. The content of endocannabinoids and the expression of cannabinoid receptor CB1 in brain tissues were determined at different time points after nicotine administration. Results showed that nicotine administration ameliorated neurological deficits and reduced infarct volume induced by cerebral ischemia in the rats. The neuroprotective effect was partially reversed by CB1 blockage. The content of the endocannabinoids N-arachidonylethanolamine and 2-arachidonoylglycerol, as well as the expression of cannabinoid receptor CB1 were up-regulated in brain tissues after nicotine delivery. These results suggest that endogenous cannabinoid system is involved in the nicotine-induced neuroprotection against transient focal cerebral ischemia.Neurochemical Research 11/2012; DOI:10.1007/s11064-012-0927-6 · 2.55 Impact Factor
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ABSTRACT: Nicotine is the main ingredient of tobacco and it has been described as aversive, reinforce and procognitive. However there is not enough research about the overlapping of the dose-dependent effects as aversive stimulus and precognitive effects. For those reasons we evaluated the nicotine effects on the Conditioned Taste Aversion paradigm (CTA) to measure the dose-response curve of the aversive effects of nicotine and to compare such effects with the procognitive effects reported. 20 male Wistar rats in standard laboratory conditions were randomly assigned to 5 groups (0.0, 0.2, 0.4, 0.8 y 1.6 mg/kg i.p.). The obtained results showed a dose-dependent decrease with a maximum effect at 1.6 mg/kg dose; however we founded effects from the 0.8 mg/kg dose, such dose overlapped with procognitive doses reported. These results allow us to propose that some effects could be due the periferical aversive effects instead of the central procognitive effects.04/2013; 3(1):930-940. DOI:10.1016/S2007-4719(13)70943-8